The Effects of Viscosity on Oropharyngeal Phase

ABSTRACT

OBJECTIVE: The videofluoroscopic swallowing study (VFSS) has been accepted for standard method of dysphagia evaluations. But there is no research for oropharyngeal effects depending on the change of viscosity. METHOD: The 10 normal subjects without dysphagia symptom or history were participated. 4 test foods were selected according to viscosity which was measured by line spread test (LST); thick semiblended diet LST 1 cm, Yoplait LST 2.44 cm, tomato juice LST 3.67 cm, 35% diluted barium LST 4.15 cm. Each foods were swallowed 3 times during VFSS. We measured oral transit time (OTT), pharyngeal delay time (PDT), pharyngeal transit time (PTT), and cricopharyngeal opening time (CPOT) RESULTS: There was linear correlation between OTT and LST (cm)(r= 0.965, P<0.05). As the score of LST increased, PDT tended to increase linearly, but there was no statistical significance (r=0.949, P=0.509). PTT and CPOT had no significant correlation with viscosity. CONCLUSION: The viscosity affected OTT and PDT. The test foods of VFSS and dysphagia diet shoud be selected by viscosity measures.